Script windows take full advantage of the language-sensitivity features of Scintilla, such as color-coded syntax, popup help, auto-completion, function parameter prompting, parentheses balancing, multi-level undo/redo, smart tabbing, block comment in/out, etc.
The popup above shows all available syntax containing "si", since that is what was typed so far.
You can also press F2 in a script window to see all available syntax options for where the cursor is located.
The cursor was indented one tabstop, under "ExitRule" within the Strategy section, so the list shows all available strategy elements.
You can also position the cursor within any syntax element and press F1. This will open the RealTest Help window with the relevant help for that syntax element.
See the Script Menu documentation for more about what can be done in a Script Window.